The present invention relates to the field of electrical connectors, and more particularly to an electrical connector and receptacle for use with portable battery packs and battery charging equipment.
Battery powered equipment, such as portable video tape recorders, typically have input jacks for the supply of power from external portable battery packs. These input jacks, however, are of generally two conductor design, and a two conductor cable couples the battery pack to the input jack via an electrical plug.
In addition to supplying power to the portable equipment, the cable leading to the battery pack should also be able to be used for conveniently charging the battery pack from an external charger. In battery chargers having a fast charging feature, it is desirable to monitor a selected condition of the battery during charging, such as battery temperature, so that the battery temperature does not exceed that temperature at which battery damage is likely to occur. In order to monitor the temperature, thermal sensors are provided integral with the battery pack and a signal is delivered to the charging equipment when the battery pack exceeds the predetermined temperature so that the charging current can be reduced or stopped. Thus, a third conductor is required in the cable leading away from the battery pack so that the cable can be coupled to both the battery charging equipment and the portable battery powered equipment. When powering the portable equipment, the temperature sensing third conductor is not used.
It is therefore an object of the present invention to provide an electrical connector which can be used for both connecting the battery pack to the battery powered equipment so as to provide power and also for connecting the battery pack to battery charging equipment which utilizes a three conductor charging circuit and which is at the same time compatible with standard battery input jacks typically found on battery powered equipment, for example, video tape recorders.
It is a further object of the present invention to provide an electrical receptacle which mates with the above connector and which can be used as the output connector in battery charging equipment which utilizes a third conductor for sensing a selected battery condition, such as temperature.